Ventilating unit

ABSTRACT

A ventilating unit within a window frame. The ventilating unit has a base panel and a top panel which extend transversely between the frame end jambs in spaced relation. A vertical exterior closure plate extends from the top panel downwardly to a level below the base panel and engages the two panels to close the exterior side of the unit. The base panel has a fresh air intake opening which communicates with an inner ventilating opening between the base panel and top panel to permit air exchange from one side of the frame to the other through the openings. An arcuate panel is slidably mounted in opposed arcuate raceways to selectively open and close the inner ventilating opening.

[ Aug. 20, 1974 VENTILATING UNIT [75] Inventors: Ronald J. Weber; Wesley J. Higgins,

both of Wausau, Wis.

[73] Assignee: Wausau Metals Corporation,

Wausau, Wis.

22 Filed: Mar. 30, 1973 211 Appl. No.: 346,281

[56] References Cited UNITED STATES PATENTS 4/1893 Almy 98/996 8/1909 Andrews.... 11/1971 Alter 98/99 R Primary Examiner-Meyer Perlin Assistant Examiner-Ronald C. Capossela Attorney, Agent, or Firm-Theodore J. Long; John M. Winter [5 7 ABSTRACT A ventilating unit within a window frame. The ventilating unit has a base panel and a top panel which extend transversely between the frame end jambs in spaced relation. A vertical exterior closure plate extends from the top panel downwardly to a level below the base panel and engages the two panels to close the exterior side of the unit. The base panel has a fresh air intake opening which communicates with an inner ventilating opening between the base panel and top panel to permit air exchange from one side of the frame to the other through the openings. An arcuate panel is slidably mounted in opposed arcuate raceways to selectively open and close the inner ventilating opening.

VENTILATING UNIT BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates generally to window ventilator units, and more particularly to ventilator units installed within the margins of a window frame.

2. Description of the Prior Art The use of ventilators in combination with operable windows has been common. One ventilator commonly used with standard double-hung windows is the hoppertype ventilator which projects from the bottom of the window frame into the building interior. Such units do not generally meet modern esthetic requirements, and the inwardly projecting components present both a safety hazard and an undesirable interference with the operation of draperies and other window accessories.

Another ventilator design employs spaced, parallel overlapping window sashes located entirely within the window frame. Such an arrangementis more suited to modern window design, but problems have been experienced in providing suitable closure mechanisms for controlling or preventing air flow through such ventilator windows. Various swinging and hinged closure arrangements have been employed in an attempt to provide a closure which is simple and convenient to operate, and which will maintain an effective air seal under conditions of both positive and negative exterior air pressure. Generally, it has been found that such swinging or hinged closures require a locking mechanism of some kind to maintain an effective air seal under all such conditions. Such locking mechanisms generally complicate the operation of the ventilator and require special attention to insure that the closure is properly sealed. In addition, locking mechanisms increase costs and usually involve moving parts which may provide maintainence and replacement problems.

SUMMARY OF THE INVENTION Our ventilating unit provides a slidable arcuate panel for controlling or preventing air flow through the unit. The arcuate panel extends for substantially the full width of the window frame in which the ventilator is located. The ends of the panel are slidably mounted in opposed arcuate raceways. The width of each raceway is adjustable to facilitate assembly and adjustment dur ing the life of the window. The arcuate panel is slidable between a lower position wherein it closes an inner ventilating opening on the interior side of the unit, and an upper position wherein the inner ventilating opening is open to permit air exchange from one side of the window frame to the other. The arcuate panel remains within the ventilating unit in all positions, without requiring any substantial head space within the unit above the inner ventilating opening.

A pile-type Weatherstrip around the arcuate panel engages the margins of the inner ventilating opening to provide a continuous air seal when the arcuate panel is in its closed position. The Weatherstrip also provides a frictional fit between the arcuate panel and adjacent raceway and sealing surfaces. The width of each raceway is adjustable to provide the amount of friction desired to maintain the panel in any desired position without requiring additional locking mechanisms.

It is a primary object of our invention to provide a ventilating unit within a window frame having a closure panel which effectively controls air flow through the unit, is simple and convenient to operate, and requires no separate locking mechanism. It is a further object of our invention to provide a ventilating unit within a window frame which employs a sliding closure panel and requires a minimum amount of head space above the inner ventilating opening. Other objects and advantages of our invention will be readily apparent from the following detailed description taken in conjunction with the accompanying drawings wherein a preferred embodiment of the invention has been selected for exemplification.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a ventilating unit exemplifying my invention, showing the ventilating unit installed in a window frame which is only partially shown.

FIG. 2 is a section view taken along line 2-2 in FIG. 1.

FIG. 3 is a partial section view taken along line 33 in FIG. 2.

FIG. 4 is a partial section view taken along line 4-4 in FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring more particularly to the drawings, wherein like numerals refer to like parts throughout the several views, FIG. 1 illustrates my ventilating unit, shown generally at 20, installed in a conventional extruded aluminum window frame 15, having an interior side 16, an exterior side 17, a lower sill l8, opposed end jambs 19a and 19b which are only partially shown in the drawings, and an upper head member (not shown).

My ventilating unit 20 includes an extruded aluminum base panel 21 which extends transversely between the opposed end jambs 19a and 19b of the window frame 15 a desired distance above the lower sill 18. The base panel 21 has a fresh air intake opening 22 to provide for the passage of ventilating air through the base panel. The fresh air opening 22 may be a single opening, or may be formed by a plurality of perforations. If desired, an insect screen 26 mounted in removable frame 27 may be removably positioned on the base panel over the fresh air intake opening 22 to prevent insects from entering the ventilating unit.

A top panel 28 also extends transversely between the opposed end jambs 19a and 19b of the window frame 15 to provide the top of the ventilating unit 20. The base panel 21 and top panel 28 are preferably secured to the end jambs 19a and 19b by conventional mortice and tenon construction. FIG. 1 shows the peened ends 23 of the base panel and top panel tenons protruding from the mortices in the end jamb 19b. An exterior closure plate 30 extends transversely between the opposed end jambs 19a and 19b and is vertically mounted on the base panel 21 and top panel 28. In the preferred embodiment, the exterior closure plate 30 is secured to the end flange 21a of the base panel 21 by means of locking flange 31 extending from the innter surface of the plate. The upper end of the plate 30 is secured to the top panel 28 by means of a plurality of mounting screws 24 which extend through mounting flange 29 depending from the top panel 28 to threadedly engage the closure plate. Caulking 32 is provided all around the closure plate 30 in a conventional manner to seal the inside of the ventilating unit 20 from moisture. In addition, the lower end 33 of the closure plate terminates at a level below that of the base panel fresh air intake 22 so that the closure plate 30 functions as a rain screen to permit ventilation during inclement weather.

Typically, our ventilator unit 20 is mounted within the window frame with glass closing the opening within the frame above the ventilator unit, and with glass or an opaque panel closing the opening defined by the frame below the ventilating unit. In the illustrated embodiment, a double glass panel 34 is mounted in the frame 15 above the top panel 28 in a conventional mannenwith caulking 35 to provide an air and moisture seal. An opaque aluminum panel 36 is mounted between the base panel 21 and the lower sill 18 of the window frame 15 near the interior side 16 of the window frame 15. The base panel 21 has a glazing channel 25 which receives the'panel 36 and caulking 37 in a conventional manner to complete the weather-tight seal between our ventilating unit and the window frame 15.

The parallel, spaced base panel 21 and top panel 28 define an inner ventilating opening represented generally by reference number 38, in the ventilating unit 20, as viewed from the interior side 16 of the window frame 15. An arcuate panel 39 is slidably mounted within the ventilating unit 20 to permit the inner ventilating opening 38 to be selectively opened or closed as desired. As best shown in FIG. 2, the preferred arcuate panel 39 includes an extruded metal panel 40 which extends for substantially the width of the inner ventilating opening 38, and an arcuate end race 41 attached to each end of the metal panel 40 by means of attachment screws 49. The end race 41 has a concave inner face 42, and a convex outer face 43 which is substantially continuous with the convex surface of the arcuate metal panel 40. The metal panel 40 and the end races 41 have a continuous Weatherstrip channel 44 which extends for substantially the entire length of the arcuate panel 39 near its upper edge 39a, and a continuous lower weatherstrip channel 45 which runs for substantiallythe entire length of the arcuate panel 39 near its lower edge 39b. As best shown in FIGS. 3 and 4, each end race 41 also has a Weatherstrip channel 46 which extends the length of the end race convex outer face 43 and intersects the upper Weatherstrip channel 44, as shown in FIG. 3, and the lower Weatherstrip channel 45. The end race 41 is preferably formed of molded nylon, and is of two-piece construction as best shown in FIGS. 3 and 4. The two pieces 41a and 41b of end race 41 have mating dowels and sockets 47 and 48, respectively, to insure proper alignment of the parts. As seen in FIG. 3, the mating parts are held together to form the end race 41 by means of the attachment screws 49 which fasten the end race to the arcuate panel metal 40.

The end race 41 of the arcuate panel 39 is slidably engaged within an adjustable raceway means indicated generally at 50 which extends between and is defined by a jamb guide 51 and a jamb filler 54, which are both preferably formed of molded nylon. The jamb guide 51 has a cylindrical external guide surface 52 which is engaged by the concave inner face 42 of the end race 41 in slidable relation. The radius of curvature of the jamb guide cylindrical guide surface 52 is substantially equal to the end race concave inner face 42. The jamb filler 54 has a concave guide surface 55 which is slidably engaged by the pile-type Weatherstrip 67 carried within the end race Weatherstrip channel 46 in slidable, substantially air-tight relation, as described in more detail below. The pile-type Weatherstrip 67 has wool or synthetic pile which slidably engages the facing surface to provide the desired air seal between the adjacent surfaces.

The jamb guides and jamb fillers are mounted on the opposed end jambs 19a and 19b in opposed relation to define opposed arcuate raceways as previously described. Each jamb guide 51 and jamb filler 54 is secured to its associated end jamb 19a or 19b as the case may be by mounting screws 56 as best shown in FIG. 2. The cylindrical jamb guide 51 has a mounting end 53 which is preferably closed except for two horizontal mounting slots 57. The mounting slots 57 permit the jamb guide 51 to be adjusted horizontally to provide a means for adjusting the width of the arcuate raceway 50 to insure that the arcuate panel 39 is slidable in the raceway 50 in the desired manner. Generally, the jamb guide 51 will be mounted so that the space between the end race convex outer face 43 and the jamb filler concave guide surface is slightly less than the normal protrusion of the Weatherstrip 67 beyond the end race convex outer face 43, so that the Weatherstrip fits snugly against the jamb filler concave guide surface 55. In that desired position, the Weatherstrip 67 will maintain a substantially air-tight seal between the facing surfaces, and will also provide sufiicient friction to maintain the arcuate panel in any position from fully closed to fully open, as desired. In the event the Weatherstrip 67 becomes worn or matted after extensive use, the jamb guide 51 can be readjusted to maintain the desired frictional air-tight fit.

When the arcuate panel 39 is in its closed position as illustrated in solid lines in FIG. 2, the Weatherstrip 68 carried in the arcuate panel upper Weatherstrip channel 44 is engaged against the upper sealing surface 58a carried by the top panel upper sealing flange 58. The Weatherstrip 69 in the lower Weatherstrip channel 45 is engaged against the lower sealing surface 60a carried by the base panel lower sealing flange 60. The upper and lower weatherstrips 68 and 69 are substantially the same as the end race Weatherstrip 67, except that the upper and lower weatherstrips include a flexible plastic vane 70 which extends longitudinally through the pile of the Weatherstrip to provide an impervious seal between the arcuate panel 39 and the upper and lower sealing surfaces 58a and 60a. The upper and lower sealing surfaces 58a and 60a extend transversely between the opposed end jambs 19a and 19b of the window frame and define the upper and lower margins, respectively, of the inner ventilating opening 38. The ends of the upper and lower sealing surfaces 58a and 60a are substantially continuous with the concave inner faces 42 of the opposed end races 41. Accordingly, the upper and lower sealing surfaces 58a and 60a, and the concave inner faces 42 of the opposed end races 41 together present a substantially continuous sealing surface against which the weatherstripping all around the arcuate panel 39 bears to provide a continuous air-tight seal between the slidable arcuate panel and the margins defining the inner ventilating opening 38.

A channel 61 extends the full width of the extruded metal panel 40 which comprises the major portion of the arcuate panel 39. The channel 61 provides a fingerhold for moving the panel 39 between its upper and lower positions. A limit stop 62 is secured within the channel 61 at each end of the metal panel 40 by means of adjustment screws 66, as best shown in FIGS. 2 and 4. The limit stop 62 has a mounting slot 63 through which the adjustment screw 66 extends to threadedly engage the metal panel 40. The limit stop 62 is secured to the panel 40 so that the outside end 64 of the limit stop is in abutment with the inwardly facing vertical surface 54a of the jamb filler 54. As these limit stops 62 at each end of the finger-hold channel 61 are so positioned, the arcuate panel 39 is prevented from moving end-wise within the ventilator unit 20, and clearance is maintained between the end races 41 which form the ends of the arcuate panel 39 and the opposed end jambs 19a and 19b of the window frame 15.

The limit stops 62 also limit the arcuate sliding movement of the arcuate panel 39 within the raceway 50 to define the upper and lower limits of its travel. The limit stops 62 each have a lower shoulder 65a which extends outwardly beyond the arcuate panel 39 to engage the near edge of the lower sealing flange 60 when the arcuate panel 39 reaches its lower closed position as best illustrated in FIG. 2. In the lower closed position illustrated, the weatherstrips 68 and 69 in the upper and lower Weatherstrip channels 44 and 45 are respectively engaged against the upper and lower sealing surfaces 58a and 60a. The dotted lines of FIG. 2 in dicate the upper open position of the arcuate panel 39 wherein the limit stop upper shoulder 65a is in engagement with the near edge of the upper sealing flange 58 to prevent further upward movement of the arcuate panel 39.

In use, the arcuate panel 39 of our ventilating unit 20 may be placed in the lower closed position illustrated in FIGS. 1 and 2 to prevent the ingress and egress of air to and from the interior of the building in which the sindow frame is mounted. The pile-type Weatherstrip maintains a positive seal against both negative and positive air pressures within the building. Since the sliding movement of the arcuate panel 39 is substantially crosswise to the direction of air flow through the inner ventilating opening 38, positive and negative air pressures have no tendency to raise the panel from its lower closed position.

If the occupant desires ventilation, he simply grasps the finger-hold channel 61 and slides the arcuate panel 39 upwardly a sufficient distance to provide the desired amount of ventilation. Ventilating air may then pass through the fresh air intake opening 22 and insect screen 26 into the interior of the ventilating unit 20, and then through the inner ventilating opening 38 into the interior of the building. If the building is subject to positive interior pressure the air flow will be in the opposite direction from that described.

The pile-type Weatherstrip 67 in the end race weatherstrip channels 46 provides a frictional contact between the arcuate panel 39 and the jamb filler concave guide surfaces 55 to retain the panel in the open position shown in dotted lines in FIG. 2, or in any desired intermediate position. The limit stop 62 limits the travel of the arcuate panel 39 in either direction by engaging the upper and lower sealing flanges 58 and 60 as previously described.

It should be noted that almost no head space is required within our ventilating unit to accommodate the sliding arcuate panel 39 in its open position. The

arcuate raceway 50 of our design allows the arcuate panel to slide within the unit in a circular path toward the exterior side of the window frame 15. Accordingly, the arcuate panel 39 and all other moving parts of our ventilating unit 20 are enclosed entirely within the confines of the ventilating unit, and within the normal dimensions of the window frame 15 within which the ventilating unit is installed.

It is understood that our invention is not confined to the particular construction and arrangement of parts herein illustrated and described, but embraces all such modified forms thereof as come within the scope of the following claims.

We claim:

1. A ventilating unit within a window frame having opposed end jambs, an interior side and an exterior side, said ventilating unit comprising,

a. a base panel extending transversely between said opposed end jambs, said base panel having at least one fresh air intake opening,

b. a top panel extending transversely between said opposed end jambs in spaced relation above said base panel to define an inner ventilating opening between said base panel and top panel,

c. an exterior closure plate extending between said opposed end jambs from said top panel to a level below said base panel at the exterior side of said window frame,

d. a pair of opposed jamb guides attached to said opposed end jambs between said base panel and said top panel, said jamb guides each having a convex guide surface,

e. a pair of opposed jamb fillers attached to said opposed end jambs, said jamb fillers each having a concave guide surface radially spaced from a said jamb guide convex guide surface to define a pair of opposed arcuate raceways between said spaced guide surfaces,

f. means for adjusting the width of said opposed arcuate raceways, and

g. an arcuate panel slidably engaged within said opposed arcuate raceways, said arcuate pane] having a lower closed position wherein said panel closes said inner ventilating opening and an upper open position wherein said ventilating opening is substantially unrestricted by said arcuate panel to permit ventilating air to pass through said ventilating unit between said fresh air intake opening and said inner ventilating opening.

2. The ventilating unit specified in claim 1 wherein the raceway adjusting means includes at least one horizontally extending mounting slot in each jamb guide, and a mounting screw extending through each said slot and threadedly engaged in each end jamb for tightening said jamb guide against said end jamb a desired distance from the spaced jamb filler.

3. The ventilating unit specified in claim 1 wherein the arcuate panel includes an arcuate end race secured to each end thereof, each said end race having a concave inner face slidably engaged on the convex guide surface of the guide jamb and a convex outer face, said convex outer face supporting a Weatherstrip in substantially air-tight slidable frictional engagement with the jamb fillerconcave guide surface.

4. The ventilating unit specified in claim 1 wherein an inner panel extends between the opposed end jambs from the base panel downwardly at the interior side of the window frame to close that portion of the frame beneath the ventilating unit, and wherein an outer panel extends between the opposed end jambs from the top panel upwardly at the exterior side of the window frame to close that portion of the frame above the ventilating unit.

5. The ventilating unit specified in claim 1 wherein a Weatherstrip extends around the periphery of the convex surface of the arcuate panel to engage the base panel, top panel and jamb fillers in a continuous manner when the arcuate panel is in its lower closed position to provide a substantially air-tight closure of the inner ventilating opening.

6. The ventilating .unit specified in claim 5 wherein the base panel and the top panel each have a sealing surface which extends between the opposed end jambs to respectively define the lower and upper margins of the inner ventilating opening, and wherein the ends of the base panel and top panel sealing surfaces respectively are approximately flush with the lower and upper ends of the concave guide surfaces of the opposed jamb fillers whereby the arcuate panel Weatherstrip will engage the said sealing surfaces and concave guide surfaces in a continuous, substantially air-tight manner when the arcuate panel is in its lower closed position.

7. The ventilating unit specified in claim 6 wherein the jamb fillers have inwardly facing vertical surfaces which define the ends of the inner ventilating opening, and wherein a limit stop is attached to the arcuate panel, near each end thereof in slidable engagement with the adjacent jamb filler inwardly facing vertical surface to prevent substantial end-to-end movement of said arcuate panel, said limit stop having a lower shoulder which engages the base panel when said arcuate panel reaches its lower closed position to prevent further downward movement thereof, and an upper shoulder which engages the top panel when said arcuate panel reaches its upper open position to prevent further upward movement thereof.

8 A ventilating unit for a window frame having opposed end jambs, an interior side and an exterior side,

comprising,

a. a base panel extending transversely between said opposed end jambs, said base panel having at least one fresh air intake opening,

- b. a top panel extending transversely between said opposed end jambs in spaced relation above said base panel to define an inner ventilating opening between said base panel and top panel,

c. an exterior closure plate extending between said opposed end jambs from said top panel to a level below said base panel at the exterior side of said window frame,

d. adjustable raceway means attached to said opposed end jambs for providing opposed arcuate raceways of adjustable width within said ventilating unit, and

e. an arcuate panel slideably engaged within said opposed raceways, said arcuate panel having a lower closed position wherein said panel closes said inner ventilating opening and an upper open position within said ventilating unit wherein ventilating air may pass from one side of said window frame to the other through said fresh air intake opening and said inner ventilating opening.

9. The ventilating unit specified in claim 8 wherein each raceway means includes a guide jamb element having a convex guide surface and a jamb filler element having a concave guide surface radially spaced from said convex surface to define the arcuate raceway between said guide surfaces, at least one of said elements being adjustably mounted on said end jamb to permit adjustment of the distance between said guide surfaces.

10. The ventilating unit specified in claim 9 wherein the jamb guide convex guide surface is a cylindrical external surface, and wherein each jamb guide has a closed end with at least one mounting slot for adjustably attaching said jamb guide to the end jamb. 

1. A ventilating unit within a window frame having opposed end jambs, an interior side and an exterior side, said ventilating unit comprising, a. a base panel extending transversely between said opposed end jambs, said base panel having at least one fresh air intake opening, b. a top panel extending transversely between said opposed end jambs in spaced relation above said base panel to define an inner ventilating opening between said base panel and top panel, c. an exterior closure plate extending between said opposed end jambs from said top panel to a level below said base panel at the exterior side of said window frame, d. a pair of opposed jamb guides attached to said opposed end jambs between said base panel and said top panel, said jamb guides each having a convex guide surface, e. a pair of opposed jamb fillers attached to said opposed end jambs, said jamb fillers each having a concave guide surface radially spaced from a said jamb guide convex guide surface to define a pair of opposed arcuate raceways between said spaced guide surfaces, f. means for adjusting the width of said opposed arcuate raceways, and g. an arcuate panel slidably engaged within said opposed arcuate raceways, said arcuate panel having a lower closed position wherein said panel closes said inner ventilating opening and an upper open position wherein said ventilating opening is substantially unrestricted by said arcuate panel to permit ventilating air to pass through said ventilating unit between said fresh air intake opening and said inner ventilating opening.
 2. The ventilating unit specified in claim 1 wherein the raceway adjusting means includes at least one horizontally extending mounting slot in each jamb guide, and a mounting screw extending through each said slot and threadedly engaged in each end jamb for tightening said jamb guide against said end jamb a desired distance from the spaced jamb filler.
 3. The ventilating unit specified in claim 1 wherein the arcuate panel includes an arcuate end race secured to each end thereof, each said end race having a concave inner face slidably engaged on the convex guide surface of the guide jamb and a convex outer face, said convex outer face supporting a weatherstrip in substantially air-tight slidable frictional engagement with the jamb filler concave guide surface.
 4. The ventilating unit specified in claim 1 wherein an inner panel extends between the opposed end jambs from the base panel downwardly at the interior side of the window frame to close that portion of the frame beneath the ventilating unit, and wherein an outer panel extends between the opposed end jambs from the top panel upwardly at the exterior side of the window frame to close that portion of the frame above the ventilating unit.
 5. The ventilating unit specified in claim 1 wherein a weatherstrip extends around the periphery of the convex surface of the arcuate panel to engage the base panel, top panel and jamb fillers in a continuous manner when the arcuate panel is in its lower closed position to provide a substantially air-tight closure of the inner ventilating opening.
 6. The ventilating unit specified in claim 5 wherein the base panel and the top panel each have a sealing surface which extends between the opposed end jambs to respectively define the lower and upper margins of the inner ventilating opening, and wherein the ends of the base panel and top panel sealing surfaces respectively are approximately flush with the lower and upper ends of the concave guide surfaces of the opposed jamb fillers whereby the arcuate panel weatherstrip will engage the said sealing surfaces and concave guide surfaces in a continuous, substantially air-tight manner when the arcuate panel is in its lower closed position.
 7. The ventilating unit specified in claim 6 wherein the jamb fillers have inwardly facing vertical surfaces which define the ends of the inner ventilating opening, and wherein a limit stop is attached to the arcuate panel, near each end thereof in slidable engagement with the adjacent jamb filler inwardly facing vertical surface to prevent substantial end-to-end movement of said arcuate panel, said limit stop having a lower shoulder which engages the base panel when said arcuate panel reaches its lower closed position to prevent further downward movement thereof, and an upper shoulder which engages the top panel when said arcuate panel reaches its upper open position to prevent further upward movement thereof. 8 A ventilating unit for a window frame having opposed end jambs, an interior side and an exterior side, comprising, a. a base panel extending transversely between said opposed end jambs, said base panel having at least one fresh air intake opening, b. a top panel extending transversely between said opposed end jambs in spaced relation above said base panel to define an inner ventilating oPening between said base panel and top panel, c. an exterior closure plate extending between said opposed end jambs from said top panel to a level below said base panel at the exterior side of said window frame, d. adjustable raceway means attached to said opposed end jambs for providing opposed arcuate raceways of adjustable width within said ventilating unit, and e. an arcuate panel slideably engaged within said opposed raceways, said arcuate panel having a lower closed position wherein said panel closes said inner ventilating opening and an upper open position within said ventilating unit wherein ventilating air may pass from one side of said window frame to the other through said fresh air intake opening and said inner ventilating opening.
 9. The ventilating unit specified in claim 8 wherein each raceway means includes a guide jamb element having a convex guide surface and a jamb filler element having a concave guide surface radially spaced from said convex surface to define the arcuate raceway between said guide surfaces, at least one of said elements being adjustably mounted on said end jamb to permit adjustment of the distance between said guide surfaces.
 10. The ventilating unit specified in claim 9 wherein the jamb guide convex guide surface is a cylindrical external surface, and wherein each jamb guide has a closed end with at least one mounting slot for adjustably attaching said jamb guide to the end jamb. 